1. Field of the Invention
This invention refer to a device and a process for controlling the motor drives of textile machines.
In a textile machine, such as for instance a fly frame In a textile machine, such as for instance a fly frame or a continuous ring frame, it is presently common to subdivide the mechanical controls of the machine""s working organs and to apply individual motor drives, for instance by using some xe2x80x9cbrushlessxe2x80x9d or asynchronous motors; these motor drives are controlled by their own systems (xe2x80x9cinvertersxe2x80x9d), whose purpose is to ensure that every working organ of the textile machine follows their rules of motion, based on certain production parameters (such as for instance the count and the twists per inch of the yarn to be produced) set up on an application program loaded on a central computer, which takes care of synchronizing the individual motor drives.
The synchronization between the individual motor drives and the method for maintaining the synchronization of the working organs within certain tolerance limits acceptable for operating the machine have recently formed the object of studies in the branch, which have engendered the production of specific processing equipment and application programs, with the inevitable consequence of appreciably adding to the costs of designing, producing and operating textile machines.
A further designing effort has led to create systems and processes capable of controlling the operation of electronically guided textile machines, based on the working parameters of the machines themselves; in the specific case, some methods for synchronizing and controlling the motor drives of fly frames are known, where the tension of the slubbing in its aerial path is due to an abnormal behavior of the twisting flyer through which it passes before being laid down on the spool by the flyer""s compressor, and certain systems synchronizing and controlling the motor drives of continuous ring frames, where the speed of motion of the ring carrier and the speed of the spools are proportional to the geometry of the yarn""s xe2x80x9cballoonxe2x80x9d.
2. Description of Related Art
The traditional control systems comprise xe2x80x9cclosed loopxe2x80x9d systems including a number of sensors placed on the machine""s working organs (for example, for the monitoring of the revolutions of the spools on a continuous fly frame), capable of transmitting the signal needed to correct the nominal revolutions of each motor drive to a processor; alternatively, the motor drives of textile machines employ some control systems of a xe2x80x9cmaster/slavexe2x80x9d type, where a reference signal is used to control the revolutions of all the textile machine""s motor drives.
However, such control processes are only based on a single reference signal, sensed by a special working organ of the textile machine; consequently, in case of a failure or a malfunction of an organ providing the reference signal, the machine operates without observing the production parameters set up in the application management program for the motor drives, despite maintaining a synchronization between this reference organ and the remaining working organs of the overall textile machine.
The purpose of this invention is therefore to overcome the mentioned drawbacks, and in particular to offer a device and a process for controlling the motor drives of textile machines, so as to ensure their safety and reliability, while not requiring the use of particularly complex or overly expensive technologies with respect to those of the known art, in relation to the available advantages.
In particular, a further purpose of this invention is to offer a device and a process for controlling the motor drives of continuous ring frames and fly frames, capable of reducing their manufacturing and operating costs with respect to those of similar machines of a traditional design.
These and other purposes are achieved by a device for controlling the motor drives of textile machines thereby increasing their efficiency, productivity and reliability.
In an advantageous manner, the use of the process according to this invention automatically eliminates the loss of time due to the stoppage of the spools or of the drawing cylinders, because of failures or malfunctions during the textile spinning, winding or other phases, with respect to those of the known technologies.
This consequently generates a greater productivity of yarn spinning with respect to that of the known art, because of the complete automation of the control process and of the relative spinning, winding and other systems; finally the manufacturing and operating costs during the production of the yarn are relatively moderate with respect to those of the known art, in relation to the advantages thus obtained.